SMALL BOAT

Abstract

 A small boat (100, 200, 300, 400) includes a forward signal output (42, 242, 342, 442) that outputs, to an engine controller (3), an output signal having an output value at which a throttle (22) opening degree increases as an operation amount of a throttle operator increases, and outputs, to the engine controller, the output signal having, as an upper limit, a limit output value at which the throttle opening degree becomes smaller than that at a maximum output voltage value at which the throttle opening degree becomes maximum.

Description

[0001] The present invention relates to a small boat.

[0002] A throttle operating device (a small boat) including a throttle operator is known in general. Such a throttle operating device (a small boat) is disclosed in Japanese Patent No. 5543224, for example.

[0003] Japanese Patent No. 5543224 discloses a lever-type throttle operating device (hereinafter referred to as a "throttle operating device") including a throttle lever. The throttle operating device includes an angle sensor that detects the rotational operation angle of the throttle lever and a board that acquires a detection signal from the angle sensor and outputs an output signal. The board outputs the output signal to an engine control unit (hereinafter referred to as an "ECU") via a wiring cord. The ECU controls driving of an engine based on the acquired output signal (detection signal).

[0004] Here, depending on an area (country) in which a small boat including a throttle operating device as disclosed in Japanese Patent No. 5543224 is operated, horsepower regulations or output regulations may be implemented by varying the upper limit of horsepower based on the license acquired by a boat operator who operates the small boat and the age of the boat operator. In order to cope with such a case, the upper limit of the output value of the output signal output from the throttle operating device may be conceivably limited by mechanically limiting the movable range of the throttle lever. For example, the throttle lever may conceivably include a stopper that mechanically limits the movable range of the throttle lever. However, in this case, an error may conceivably be caused in the limited upper limit of the output value of the output signal output from the throttle operating device due to an error in the mounting position of the stopper or an error in the shape (size) of the stopper (an error due to the structure that mechanically limits the movable range). Therefore, a small boat in which the horsepower is more accurately limited has been desired.

[0005] It is an object of the present invention to provide small boat and throttle operating method for a small boat in which the horsepower is more accurately limited. Accordingly to the present invention said object is solved by a small boat having the features of independent claim 1. Moreover, said object is also solved by a throttle operating method for a small boat having the features of independent claim 15. Preferred embodiments are laid down in the dependent claims.

[0006] A small boat according to a preferred embodiment includes a throttle operator through which a throttle opening degree of an engine is controlled, an engine controller that is configured to control the throttle opening degree, and an forward signal output that is configured to output, to the engine controller, an output signal having an output value at which the throttle opening degree increases as an operation amount of the throttle operator increases, and is configured to output, to the engine controller, the output signal having, as an upper limit, a limit output value at which the throttle opening degree becomes smaller than that at a maximum output voltage value at which the throttle opening degree becomes maximum.

[0007] In a small boat according to a preferred embodiment, the forward signal output is configured to output, to the engine controller, the output signal having, as an upper limit, the limit output value at which the throttle opening degree becomes smaller than that at the maximum output value at which the throttle opening degree becomes maximum. Accordingly, the horsepower of the small boat (engine) is limited to an amount corresponding to the limit output value without limiting the upper limit of the operation amount of the throttle operator (without mechanically limiting the movable range). Consequently, unlike the case in which the movable range of the throttle operator is mechanically limited, no error is caused due to the structure that limits the movable range, and thus the upper limit of the output signal is more accurately limited. That is, the horsepower is more accurately limited as compared with the case in which the movable range of the throttle operator is mechanically limited. In addition, even when the maximum horsepower (the amount of horsepower to be a specification value) of the engine mounted on the small boat is larger than the horsepower corresponding to the limit output value (the amount of horsepower limited by laws and regulations, for example), the horsepower of the engine of the small boat is limited to an amount corresponding to the limit output value. Thus, it is not necessary to prepare the engine that sets the horsepower corresponding to the limit output value to the maximum horsepower separately from the engine having the maximum horsepower larger than the horsepower corresponding to the limit output value, and thus an increase in the number of engine types in the small boat is significantly reduced or prevented. Consequently, the small boat complies with horsepower regulations while an increase in the number of engine types is significantly reduce or prevented. In addition, when the horsepower is limited by the engine controller (ECU), it is necessary to prepare a plurality of types of control programs of the engine controller. In this case, it is necessary to design the control program of the engine controller for each limited horsepower, and when the control program is changed, an inspection to operate the engine controller is required for each small boat. Thus, the number of inspection steps is increased. On the other hand, according to preferred embodiments, the forward signal output is configured to output the output signal having the limit output value as an upper limit to the engine controller such that the horsepower of the small boat is limited by changing (replacing) the output (throttle operating device, for example) without changing the control program of the engine controller. Thus, the small boat complies with horsepower regulations while the number of inspection steps of the engine controller that operates the entire small boat is reduced as compared with the case in which the control program of the engine controller (ECU) is changed.

[0008] In a small boat according to a preferred embodiment, the forward signal output is configured to output the output signal having the limit output value to the engine controller when the operation amount is a maximum operation amount. Accordingly, even when the throttle operator is operated to the maximum operation amount (when the operation amount of the throttle operator is not limited), the output signal having the limit output value as an upper limit is output, and thus the small boat complies with horsepower regulations without changing the range (movable range) of the operation amount of the throttle operator.

[0009] In such a case, the forward signal output is configured to output the output signal having the limit output value to the engine controller when the operation amount is equal to or larger than an operation amount threshold that is smaller than the maximum operation amount. Accordingly, output of the output signal that exceeds the limit output value is prevented even when the throttle operator is operated to the operation amount equal to or larger than the predetermined operation amount threshold.

[0010] In a small boat in which the output signal having the limit output value is output when the operation amount is the maximum operation amount, the forward signal output is configured to output, to the engine controller, the output signal having the output value at which the throttle opening degree increases as the operation amount increases over a range from the operation amount of 0 to the maximum operation amount. Accordingly, the output value corresponding to the operation amount is output (the throttle opening degree is adjusted) over the range from the operation amount of 0 to the maximum operation amount while the upper limit of the output value is limited to the limit output value, and thus while the small boat complies with horsepower regulations, the output value is more precisely adjusted as compared with the case in which the output signal having the limit output value (constant value) at the operation amount equal to or larger than the operation amount threshold is output.

[0011] In such a case, the forward signal output is configured to output, to the engine controller, the output signal having the output value at which the throttle opening degree increases as the operation amount increases such that the operation amount and the output value have a linear function relationship over the range from the operation amount of 0 to the maximum operation amount. Accordingly, even when the upper limit of the output value is limited to the limit output value, a boat operator more intuitively adjusts the output value as compared with the case in which the operation amount and the output value have a relatively complicated relationship (output characteristics) other than the linear function.

[0012] In a small boat in which the output signal having the limit output value is output when the operation amount is the maximum operation amount, the throttle operator is preferably rotationally operated, the small boat preferably further includes an angle detector that is configured to detect a rotation angle of the throttle operator, and the forward signal output is configured to output the output signal having the limit output value, assuming that the operation amount is the maximum operation amount, to the engine controller when the rotation angle that is detected by the angle detector is a maximum angle. Accordingly, the upper limit of the output value of the output signal is limited to the limit output value without limiting the rotation angle of the throttle operator to an angle smaller than the maximum angle (without changing the movable range).

[0013] In such a case, the throttle operator preferably extends from a rotation shaft disposed in a vicinity of a grip grasped by a boat operator in a radial direction of the rotation shaft, and is preferably a lever that is configured to be rotated about the rotation shaft toward the grip, the angle detector preferably faces the rotation shaft in the radial direction, and is configured to detect a rotation angle of the rotation shaft as the operation amount, and the forward signal output is configured to output the output signal having the limit output value, assuming that the operation amount is the maximum operation amount, to the engine controller when the rotation angle that is detected by the angle detector is the maximum angle. Here, a small boat may conceivably include an angle detector disposed away from a rotation shaft of a lever and that detects the rotation angle of the rotation shaft via a mechanical wire provided on the rotation shaft. However, in such a small boat, due to the mechanical wire, the number of components increases, and the load required to rotate the lever increases. On the other hand, according to preferred embodiments, the angle detector faces the rotation shaft in the radial direction and detects the rotation angle of the rotation shaft as the operation amount such that the rotation angle is detected without providing a mechanical wire, and the output signal corresponding to the rotation angle is output to the engine controller. Consequently, a mechanical wire is not provided, and thus an increase in the number of components in the small boat is significantly reduced or prevented while an increase in the load required to rotate the lever is significantly reduced or prevented.

[0014] In a small boat according to a preferred embodiment, the forward signal output is configured to output the output signal having the output value corresponding to the operation amount to the engine controller based on output limitation characteristics information in which the output value including the limit output value as an upper limit and the operation amount are associated with each other. Accordingly, the output easily generates the output signal having the output value corresponding to the operation amount and including the limit output value as an upper limit, referring to the output limitation characteristics information, and outputs the output signal to the engine controller.

[0015] In such a case, in the output limitation characteristics information, the operation amount and an output voltage value as the output value are preferably associated with each other, and the forward signal output is configured to output the output signal having a limit output voltage value, which is the output voltage value corresponding to the limit output value, as an upper limit to the engine controller. Accordingly, the forward signal output is configured to output the voltage value corresponding to the operation amount, referring to the output limitation characteristics information, and thus the forward signal output is configured to easily output the output signal having the output value including the limit output value as an upper limit.

[0016] A small boat in which the output signal is output based on the output limitation characteristics information preferably further includes a setter that is configured to set one of the output limitation characteristics information and output non-limitation characteristics information in which the output value including the maximum output voltage value as an upper limit and the operation amount are associated with each other, and the forward signal output is configured to output the output signal having the output value corresponding to the operation amount to the engine controller based on one of the output limitation characteristics information and the output non-limitation characteristics information set by the setter. Accordingly, setting of the output limitation characteristics information and the output non-limitation characteristics information is switched such that output signals having different output values as upper limits are output from the output using the same type of engine (small boat). Consequently, the upper limit of the output value of the output signal is changed according to the limited horsepower (horsepower regulations) using the same type of engine (small boat), and thus even when the boat operator is changed (to a boat operator with a different license) or even when the small boat is moved across countries in which different horsepower regulations are set up, the small boat complies with horsepower regulations.

[0017] In such a case, the setter preferably includes a setting operator that is configured to receive an operation of setting one of the output limitation characteristics information and the output non-limitation characteristics information. Accordingly, the boat operator or a setting worker operates the setting operator to easily set (select) one of the output limitation characteristics information and the output non-limitation characteristics information.

[0018] When the small boat includes the setter, the output preferably includes a storage that is configured to store the output limitation characteristics information and the output non-limitation characteristics information. Accordingly, the output limitation characteristics information and the output non-limitation characteristics information are stored in the storage of the output, and thus the output signal is generated using the output limitation characteristics information and the output non-limitation characteristics information stored in the storage without providing the output limitation characteristics information and the output non-limitation characteristics information separately from the output (small boat).

[0019] In a small boat in which the output signal having the limit output value is output when the operation amount is the maximum operation amount, the output preferably includes a maximum signal output that is configured to output a maximum signal, which is a signal having the maximum output voltage value, when the operation amount is the maximum operation amount, and an output limiter that is configured to output the output signal in a state in which the maximum output voltage value of the maximum signal output from the maximum signal output is reduced to the limit output value when the operation amount is the maximum operation amount, or is configured to output the output signal in a state in which the maximum output voltage value of the maximum signal output from the maximum signal output is limited to the limit output value when the operation amount is equal to or larger than an operation amount threshold that is smaller than the maximum operation amount. Accordingly, the output limiter is added to the structure of the existing output such that the output easily outputs the output signal having the limit output value as an upper limit.

[0020] A small boat according to a preferred embodiment preferably further includes a throttle operating device main body in which the throttle operator and the output are disposed and being replaceable from a boat body. Accordingly, a throttle operating device main body to which the output signal having the maximum output value as an upper limit is output from the output is replaced with the throttle operating device main body to which the output signal having the limit output value as an upper limit is output from the output such that a state in which the upper limit of the output value of the output signal output from the output becomes the maximum output value is easily changed to a state in which the upper limit of the output value of the output signal output from the output becomes the limit output value using the same type of engine.

[0021] In such a case, on the throttle operating device main body, it is preferably visually distinguishable that an upper limit of the output value of the output signal is limited to the limit output value. Accordingly, even when the same type of engine is used, the boat operator recognizes whether or not the upper limit of the output value of the output signal output from the output is limited to the limit output value by visually recognizing the throttle operating device main body.

[0022] The above and other elements, features, steps, characteristics and advantages of preferred embodiments will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 

Fig. 1 is a side sectional view showing the overall structure of a small boat according to a first preferred embodiment.

Fig. 2 is a block diagram showing the structure of the small boat according to the first preferred embodiment.

Fig. 3 is a plan view showing the structure of a handle unit according to the first preferred embodiment.

Fig. 4 is a plan view showing the structure of a forward throttle operating unit according to the first preferred embodiment.

Fig. 5 is a diagram illustrating detection of a rotation angle according to the first preferred embodiment.

Fig. 6 is a diagram illustrating characteristics information according to the first preferred embodiment.

Fig. 7 is a diagram illustrating characteristics information according to a second preferred embodiment.

Fig. 8 is a block diagram showing the structure of a small boat according to a third preferred embodiment.

Fig. 9 is a diagram illustrating unlimited characteristics information according to the third preferred embodiment.

Fig. 10 is a diagram illustrating the placement position of a setting operator according to the third preferred embodiment.

Fig. 11 is a block diagram showing the structure of a small boat according to a fourth preferred embodiment.

Fig. 12 is a diagram illustrating the structure of a forward signal output according to the fourth preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Preferred embodiments are hereinafter described with reference to the drawings.

First Preferred Embodiment

[0025] The structure of a small boat 100 according to a first preferred embodiment is now described with reference to Figs. 1 to 6. The small boat 100 is a personal watercraft (PWC), for example, and is a water jet propelled boat (water motorcycle). That is, the small boat 100 is a straddled watercraft.

[0026] As shown in Fig. 1, the small boat 100 includes a boat body 1, an engine 2, an engine controller 3, a fuel tank 4, a fuel injection system 5 (hereinafter referred to as an "FI system 5"), and a handle unit 6 including a forward throttle operating unit 10a (hereinafter referred to as a "forward operating unit 10a"). The forward throttle operating unit 10a is an example of a "throttle operating device" or a "throttle operating device main body".

[0027] The boat body 1 includes a deck 1a and a hull 1b. The boat body 1 is immersed up to a predetermined height (a water surface T in Fig. 1) in a stationary state. An engine room 1c that houses the engine 2 driven when the boat body 1 is propelled, the engine controller 3, the fuel tank 4, and the Fl system 5 is provided in the boat body 1.

[0028] The engine 2 obtains a drive force to rotate a crankshaft 21 by burning an air-fuel mixture in a combustion chamber. Specifically, the engine 2 includes a throttle valve 22 and a throttle valve actuator 23. The opening degree (throttle opening degree) of the throttle valve 22 is changed by the throttle valve actuator 23 such that the amount of air supplied to the combustion chamber of the engine 2 is adjusted. As the opening degree of the throttle valve 22 increases, the rotational speed of the engine 2 increases, and the horsepower of the engine 2 increases. The Fl system 5 includes a fuel injection system that supplies fuel at the predetermined timing and an ignition system that ignites an air-fuel mixture at the predetermined timing. The throttle valve actuator 23 and the FI system 5 are electrically connected to the engine controller 3, and are controlled based on commands from the engine controller 3.

[0029] The crankshaft 21 is connected to an impeller shaft 24 via a coupling (not shown). The impeller shaft 24 extends rearward from the engine room 1c. An impeller 25 is attached in the vicinity of a rear end of the impeller shaft 24. The impeller 25 is disposed inside an impeller housing 1e connected to a rear portion of a water intake 1d, suctions water below the water surface T from the water intake 1d, and jets the water rearward from a nozzle 1f provided behind the impeller housing 1e.

[0030] The boat body 1 includes a deflector 1g and a bucket 1h. The deflector 1g is located behind the nozzle 1f, and changes the direction of the water jetted rearward from the nozzle 1f to a right-left direction. The handle unit 6 is operated such that the orientation of the deflector 1g is changed via a steering cable (not shown) connected to a steering shaft 62 (see Fig. 3) of the handle unit 6 described below. That is, when a pair of grips 12 described below are operated by a rider P, the orientation of the deflector 1g is changed, and the small boat 100 is steered.

[0031] The bucket 1h is moved between the upper side and the rear side of the deflector 1g by a bucket actuator 1i. When the bucket 1h is moved to the rear side of the deflector 1g, the bucket 1h changes the direction of water jetted rearward from the nozzle 1f and the deflector 1g to a forward direction. The driving of the bucket actuator 1i is controlled by the engine controller 3, as shown in Fig. 2.

[0032] As shown in Fig. 1, a seat 1j on which the rider P is seated and the handle unit 6 operated to steer the boat body 1 are provided on a portion of the deck 1a above the engine 2 in the boat body 1. The handle unit 6 is disposed in front of the seat 1j.

[0033] As shown in Fig. 2, the engine controller 3 is an ECU (engine control unit), and controls the driving of the engine 2 based on an operation signal (output signal S) from the handle unit 6. Specifically, the engine controller 3 is electrically connected to the forward operating unit 10a (forward signal output 42) and a rearward throttle operating unit 10b (hereinafter referred to as a "rearward operating unit 10b"). The engine controller 3 controls the driving of the bucket actuator 1i, the FI system 5, and the throttle valve actuator 23 based on a control program.

[0034] The engine controller 3 drives the throttle valve actuator 23 such that the opening degree of the throttle valve 22 increases as the output voltage value V of the acquired output signal S increases. When acquiring a maximum output voltage value V_M, the engine controller 3 drives the throttle valve actuator 23 such that the opening degree of the throttle valve 22 is maximum (fully opened, for example).

[0035] When the output voltage value V of the output signal S from the forward operating unit 10a is larger than the output voltage value V of the output signal S from the rearward operating unit 10b, the engine controller 3 controls the bucket actuator 1i to move the bucket 1h to the upper side of the deflector 1g so as to move the small boat 100 forward. When the output voltage value V of the output signal S from the forward operating unit 10a is smaller than the output voltage value V of the output signal S from the rearward operating unit 10b, the engine controller 3 controls the bucket actuator 1i to move the bucket 1h to the rear side of the deflector 1g so as to move the small boat 100 rearward.

[0036] According to the first preferred embodiment, when acquiring the output signal S having the output voltage value V less than an abnormality detection output voltage value Ve described below from the forward operating unit 10a or the rearward operating unit 10b, the engine controller 3 stops the driving of the engine 2 or sets the engine 2 to idle. Note that the term "idle" indicates a state in which the engine controller 3 controls the throttle valve actuator 23 and the FI system 5 such that the engine 2 reaches a rotational speed within an idling rotational speed range. That is, when acquiring the output signal S having the output voltage value V (0 [V], for example) less than the abnormality detection output voltage value Ve as a lower limit from the forward operating unit 10a or the rearward operating unit 10b, the engine controller 3 detects the abnormality of the forward operating unit 10a or the rearward operating unit 10b, or the abnormality of wiring between the forward operating unit 10a or the rearward operating unit 10b and the engine controller 3.

[0037] As shown in Fig. 3, the handle unit 6 includes the forward operating unit 10a grasped by the right hand and the rearward operating unit 10b grasped by the left hand, for example, when the rider P steers. Furthermore, the handle unit 6 includes a handle main body 61 to which the forward operating unit 10a and the rearward operating unit 10b are attached. According to the first preferred embodiment, the forward operating unit 10a and the rearward operating unit 10b are replaceable (detachable) from the handle main body 61. For example, the forward operating unit 10a and the rearward operating unit 10b shown by solid lines are detachable from a dotted portion of the handle main body 61 shown in Fig. 3 by removing fasteners (not shown).

[0038] The handle main body 61 includes the steering shaft 62 and a case 63 that covers the steering shaft 62. The steering shaft 62 rotates in response to the positions of the forward operating unit 10a and the rearward operating unit 10b. The steering shaft 62 transmits the rotation to the deflector 1g via the steering cable (not shown).

[0039] As shown in Fig. 4, according to the first preferred embodiment, the forward operating unit 10a includes a throttle lever 11 (hereinafter referred to as a "lever 11") that controls the opening degree (throttle opening degree) of the throttle valve 22 of the engine 2, a grip 12 grasped by the rider P, and an operating unit housing 13 to which the lever 11 and the grip 12 are attached. The lever 11 is operated by being rotated with respect to the operating unit housing 13. The lever 11 is an example of a "throttle operator".

[0040] As shown in Fig. 5, the forward operating unit 10a includes an angle detector 41, the forward signal output 42, and a board 43 disposed inside the operating unit housing 13. An accelerator position sensor (APS) includes the angle detector 41 and the forward signal output 42. The angle detector 41 detects the operation amount (the rotation angle θ described below) of the lever 11. The forward signal output 42 outputs the output signal S to the engine controller 3 based on a detection signal (information about the rotation angle θ) from the angle detector 41. The angle detector 41 and the forward signal output 42 are disposed on the board 43, for example. The forward signal output 42 is mounted as an element on the board 43. The forward signal output 42 is an example of an "output".

[0041] The forward signal output 42 is electrically connected to the engine controller 3 (see Fig. 2). As shown in Fig. 6, according to the first preferred embodiment, the forward signal output 42 outputs the output signal S having the output voltage value V at which the opening degree of the throttle valve 22 increases as the rotation angle θ of the lever 11 increases, and outputs the output signal S having, as an upper limit, the limit output voltage value Vr at which the opening degree of the throttle valve 22 becomes smaller than that at the maximum output voltage value V_M at which the opening degree of the throttle valve 22 becomes maximum, to the engine controller 3.

[0042] On the forward operating unit 10a, it is visually distinguishable that the upper limit of the output voltage value V of the output signal S is limited to the limit output voltage value Vr. Specifically, on the lever 11 shown in Fig. 4, it is distinguishable by color that the upper limit of the output voltage value V of the output signal S is limited to the limit output voltage value Vr. More specifically, the color of the lever 11 according to the first preferred embodiment is different from the color of a lever in which the upper limit of the output voltage value V of the output signal S is set (not limited) to the maximum output voltage value V_M. That is, when visually recognizing the color of the lever 11, the rider P determines whether the lever 11 (forward operating unit 10a) according to the first preferred embodiment is mounted on the small boat 100 or an unlimited lever (forward operating unit) is mounted on the small boat 100.

[0043] As shown in Fig. 4, the forward operating unit 10a includes a rotation shaft 14. The rotation shaft 14 is a shaft that serves as the rotation center of the lever 11. According to the first preferred embodiment, the lever 11 extends from the rotation shaft 14 in the radial direction of the rotation shaft 14, and rotates about the rotation shaft 14 from a rotation angle of 0 degrees (θ = 0) to a maximum angle θ_M (θ = θ_M) toward the grip 12. The maximum angle θ_M is an example of a "maximum operation amount".

[0044] The rotation shaft 14 is fixed to the operating unit housing 13 so as to be rotatable integrally with the lever 11 with respect to the operating unit housing 13. For example, the rotation shaft 14 is fixed to the operating unit housing 13 via a biasing member (not shown). A biasing force is applied to the rotation shaft 14 by the biasing member, and when the rider P does not grasp the lever 11, the rotation shaft 14 moves (returns) the lever 11 to the position at a rotation angle of 0 degrees.

[0045] As shown in Fig. 5, the angle detector 41 faces the rotation shaft 14 in the radial direction, and detects the rotation angle θ of the rotation shaft 14 as a rotation angle that serves as the operation amount. Specifically, the angle detector 41 is an element (magnetic detection element) that detects a magnetic change, for example. The angle detector 41 is mounted on the board 43. The rotation shaft 14 includes a magnet 15. For example, the thickness of the magnet 15 in the radial direction is non-uniform in a circumferential direction such that the magnitude of the magnetism detected by the angle detector 41 varies according to the rotation angle θ of the rotation shaft 14. Thus, the angle detector 41 outputs a detection signal having a voltage value corresponding to the rotation angle θ of the rotation shaft 14 to the forward signal output 42 via a circuit on the board 43.

[0046] As shown in Fig. 2, the forward signal output 42 includes a processor 51 including a CPU (central processing unit), for example, and a storage 52 (nonvolatile memory, for example) that stores a control program 52a and characteristics information 52b described below in advance. The processor 51 performs control processing based on the rotation angle θ acquired from the angle detector 41 and the control program 52a and the characteristics information 52b stored in the storage 52. The characteristics information 52b is an example of "output limitation characteristics information".

[0047] As shown in Fig. 6, the characteristics information 52b is data in which the output voltage value V including the limit output voltage value Vr as an upper limit and the rotation angle θ are associated with each other. According to the first preferred embodiment, the output signal S having the output voltage value V corresponding to the rotation angle θ is output to the engine controller 3 based on (referring to) the characteristics information 52b. Specifically, in the characteristics information 52b, the abnormality detection output voltage value Ve (lower limit) is set as the output voltage value V corresponding to a rotation angle of 0 degrees (the operation amount is 0). The abnormality detection output voltage value Ve is a voltage value larger than 0 [V] and smaller than the limit output voltage value Vr, for example. The abnormality detection output voltage value Ve is an example of an "abnormality detection output value".

[0048] In the characteristics information 52b, the output voltage value V at which the opening degree of the throttle valve 22 increases as the rotation angle θ increases over a range R1 from a rotation angle of 0 degrees to a threshold angle θt, which is the rotation angle θ smaller than the maximum angle θ_M, is set. That is, when the rotation angle θ is larger than 0 degrees, the forward signal output 42 outputs the output signal S having the output voltage value V larger than the abnormality detection output voltage value Ve. The threshold angle θt is an example of an "operation amount threshold".

[0049] Specifically, in the characteristics information 52b, the output voltage value V at which the opening degree of the throttle valve 22 increases as the rotation angle θ increases such that the rotation angle θ and the output voltage value V have a substantially linear function relationship (proportional relationship) is set. That is, according to the first preferred embodiment, the forward signal output 42 outputs, to the engine controller 3, the output signal S having the output voltage value V at which the opening degree of the throttle valve 22 increases as the rotation angle θ increases such that the rotation angle θ and the output voltage value V have a substantially linear function relationship (proportional relationship).

[0050] A dotted portion in Fig. 6 shows data (hereinafter referred to as "non-limitation information") in which the output voltage value V including the maximum output voltage value V_M as an upper limit (not limited) and the rotation angle θ are associated with each other. Here, the characteristics of a portion (range R1) of the characteristics information 52b in which the rotation angle θ and the output voltage value V have a substantially linear function relationship are substantially the same as the characteristics of the range R1 of the non-limitation information. That is, in the range R1, the forward signal output 42 outputs the same output signal S as when the output voltage value V is not limited.

[0051] In the characteristics information 52b, the limit output voltage value Vr (constant value) is set in a range R2 in which the rotation angle θ is not less than the threshold angle θt and not more than the maximum angle θ_M. That is, according to the first preferred embodiment, when the rotation angle θ detected by the angle detector 41 is the maximum angle θ_M (in the range R2 of not less than the threshold angle θt and not more than the maximum angle θ_M), the forward signal output 42 outputs the output signal S having the limit output voltage value Vr, assuming that the operation amount of the lever 11 is the maximum operation amount, to the engine controller 3. The structure of the rearward operating unit 10b is similar to the structure of the forward operating unit 10a, and thus description thereof is omitted.

[0052] According to the first preferred embodiment, the following advantageous effects are achieved.

[0053] According to the first preferred embodiment, the forward signal output 42 outputs, to the engine controller 3, the output signal S having, as an upper limit, the limit output voltage value Vr at which the opening degree of the throttle valve 22 becomes smaller than that at the maximum output voltage value V_M at which the opening degree of the throttle valve 22 becomes maximum. Accordingly, the horsepower of the small boat 100 (engine 2) is limited to an amount corresponding to the limit output voltage value Vr without limiting the upper limit of the rotation angle θ of the lever 11 (without mechanically limiting the movable range). Consequently, unlike the case in which the movable range of the lever 11 is mechanically limited, no error is caused due to the structure that limits the movable range, and thus the upper limit of the output signal S is more accurately limited. That is, the horsepower is more accurately limited as compared with the case in which the movable range of the lever 11 is mechanically limited. In addition, even when the maximum horsepower (the amount of horsepower to be a specification value) of the engine 2 mounted on the small boat 100 is larger than the horsepower corresponding to the limit output voltage value Vr (the amount of horsepower limited by laws and regulations, for example), the horsepower of the engine 2 of the small boat 100 is limited to an amount corresponding to the limit output voltage value Vr. Thus, it is not necessary to prepare the engine 2 that sets the horsepower corresponding to the limit output voltage value Vr to the specification value (maximum horsepower) separately from the engine 2 having the maximum horsepower larger than the horsepower corresponding to the limit output voltage value Vr, and thus an increase in the number of engine 2 types in the small boat 100 is significantly reduced or prevented. Consequently, the small boat 100 complies with horsepower regulations while an increase in the number of engine 2 types is significantly reduce or prevented. Furthermore, according to the first preferred embodiment, the forward signal output 42 outputs the output signal S having the limit output voltage value Vr as an upper limit to the engine controller 3 such that the horsepower of the small boat 100 is limited by changing (replacing) the forward operating unit 10a without changing the control program of the engine controller 3. Thus, the small boat 100 complies with horsepower regulations while the number of inspection steps of the engine controller 3 that operates the entire small boat 100 is reduced as compared with the case in which the control program of the engine controller 3 (ECU) is changed.

[0054] According to the first preferred embodiment, the forward signal output 42 outputs the output signal S having the limit output voltage value Vr to the engine controller 3 when the operation amount (rotation angle θ) is the maximum operation amount (maximum angle θ_M). Accordingly, even when the lever 11 is operated from the rotation angle θ to the maximum angle θ_M (when the rotation angle θ of the lever 11 is not limited), the output signal S having the limit output voltage value Vr as an upper limit is output, and thus the small boat 100 complies with horsepower regulations without changing the range (movable range) of the operation amount of the lever 11.

[0055] According to the first preferred embodiment, the forward signal output 42 outputs the output signal S having the limit output voltage value Vr to the engine controller 3 when the operation amount (rotation angle θ) is equal to or larger than the threshold angle θt smaller than the maximum operation amount (maximum angle θ_M). Accordingly, output of the output signal S that exceeds the limit output voltage value Vr is prevented even when the lever 11 is operated to the rotation angle θ equal to or more than the predetermined threshold angle θt.

[0056] According to the first preferred embodiment, the lever 11 is rotationally operated. Furthermore, the forward operating unit 10a includes the angle detector 41 that detects the rotation angle θ of the lever 11. When the rotation angle θ detected by the angle detector 41 is the maximum angle θ_M, the forward signal output 42 outputs the output signal S having the limit output voltage value Vr, assuming that the operation amount is the maximum operation amount, to the engine controller 3. Accordingly, the upper limit of the output voltage value V of the output signal S is limited to the limit output voltage value Vr without limiting the rotation angle θ of the lever 11 to an angle smaller than the maximum angle θ_M (without changing the movable range).

[0057] According to the first preferred embodiment, the lever 11 extends from the rotation shaft 14 disposed in the vicinity of the grip 12 grasped by the rider P in the radial direction of the rotation shaft 14, and is rotatable about the rotation shaft 14 toward the grip 12. Furthermore, the angle detector 41 faces the rotation shaft 14 in the radial direction, and detects the rotation angle θ of the rotation shaft 14 as the operation amount. When the rotation angle θ detected by the angle detector 41 is the maximum angle θ_M, the forward signal output 42 outputs the output signal S having the limit output voltage value Vr, assuming that the operation amount is the maximum operation amount, to the engine controller 3. Accordingly, the rotation angle θ is detected without providing a mechanical wire, and the output signal S corresponding to the rotation angle θ is output to the engine controller 3. Consequently, a mechanical wire is not provided, and thus an increase in the number of components in the small boat 100 is significantly reduced or prevented, and an increase in the load required to rotate the lever 11 is significantly reduced or prevented.

[0058] According to the first preferred embodiment, the forward signal output 42 outputs the output signal S having the output voltage value V corresponding to the rotation angle θ to the engine controller 3 based on the characteristics information 52b in which the output voltage value V (output value) including the limit output voltage value Vr (limit output value) as an upper limit and the rotation angle θ (operation amount) are associated with each other. Accordingly, the forward signal output 42 easily generates the output signal S having the output voltage value V corresponding to the rotation angle θ and including the limit output voltage value Vr as an upper limit, referring to the characteristics information 52b, and outputs the output signal S to the engine controller 3.

[0059] According to the first preferred embodiment, in the characteristics information 52b, the rotation angle θ and the output voltage value V as the output value are associated with each other. Furthermore, the forward signal output 42 outputs the output signal S having the limit output voltage value Vr, which is the output voltage value V corresponding to the limit output value, as an upper limit to the engine controller 3. Accordingly, the forward signal output 42 outputs the voltage value corresponding to the rotation angle θ, referring to the characteristics information 52b, and thus the forward signal output 42 easily outputs the output signal S having the output voltage value V including the limit output voltage value Vr as an upper limit.

[0060] According to the first preferred embodiment, the forward operating unit 10a includes the lever 11 and the forward signal output 42, and is replaceable from the boat body 1. Accordingly, a forward operating unit to which the output signal S having the maximum output voltage value V_M as an upper limit is output from the forward signal output is replaced with the forward operating unit 10a to which the output signal S having the limit output voltage value Vr as an upper limit is output from the forward signal output 42 such that a state in which the upper limit of the output voltage value V of the output signal S output from the forward signal output 42 becomes the maximum output voltage value V_M is easily changed to a state in which the upper limit of the output voltage value V of the output signal S output from the forward signal output 42 becomes the limit output voltage value Vr using the same type of engine 2.

[0061] According to the first preferred embodiment, on the forward operating unit 10a (preferably the lever 11), it is visually distinguishable that the upper limit of the output voltage value V of the output signal S is limited to the limit output voltage value Vr. Accordingly, even when the same type of engine 2 is used, the rider P recognizes whether or not the upper limit of the output voltage value V of the output signal S output from the forward signal output 42 is limited to the limit output voltage value Vr by visually recognizing the forward operating unit 10a.

[0062] According to the first preferred embodiment, on the forward operating unit 10a (preferably the lever 11), it is distinguishable by color that the upper limit of the output voltage value V of the output signal S is limited to the limit output voltage value Vr. Accordingly, the color of the forward operating unit 10a in which the upper limit of the output voltage value V of the output signal S output from the forward signal output 42 is limited to the limit output voltage value Vr is made different from the color of a forward operating unit in which the upper limit of the output voltage value V is not limited to the limit output voltage value Vr such that the rider P more intuitively recognizes whether or not the upper limit of the output voltage value V of the output signal S is limited to the limit output voltage value Vr.

[0063] According to the first preferred embodiment, the forward signal output 42 outputs the abnormality detection output voltage value Ve as the output signal S to the engine controller 3 when the rotation angle θ is 0, and outputs the output signal S having the limit output voltage value Vr, which is larger than the abnormality detection output voltage value Ve, as an upper limit to the engine controller 3 when the rotation angle θ is larger than 0. Furthermore, the engine controller 3 stops the engine 2 or sets the engine 2 to idle when acquiring the output signal S having the output voltage value V less than the abnormality detection output voltage value Ve. Accordingly, the small boat 100 includes an abnormality detection function of stopping the engine 2 or setting the engine 2 to idle when acquiring the output signal S having the output voltage value V less than the abnormality detection output voltage value Ve, and the output signal S having the limit output voltage value Vr as an upper limit is output to the engine controller 3.

Second Preferred Embodiment

[0064] The structure of a small boat 200 according to a second preferred embodiment is now described with reference to Figs. 1 and 7. In the small boat 200 according to the second preferred embodiment, an output signal S having an output voltage value V at which the opening degree of a throttle valve 22 increases as the rotation angle θ of a lever 11 increases over a range R3 from a rotation angle of 0 degrees to a maximum angle θ_M is output, unlike the small boat 100 according to the first preferred embodiment in which the constant limit output voltage value Vr is output when the rotation angle θ is equal to or more than the threshold angle θt. In the second preferred embodiment, the same structures as those of the first preferred embodiment are denoted by the same reference numerals, and description thereof is omitted.

[0065] As shown in Fig. 2, the small boat 200 according to the second preferred embodiment includes a handle unit 206. The handle unit 206 includes a forward operating unit 210a and a rearward operating unit 210b. The forward operating unit 210a includes a forward signal output 242. The forward signal output 242 includes a storage 252 that stores characteristics information 252b.

[0066] As shown in Fig. 7, according to the second preferred embodiment, in the characteristics information 252b, the rotation angle θ and the output voltage value V including a limit output voltage value Vr as an upper limit are associated with each other such that the rotation angle θ and the output voltage value V have a substantially linear function relationship over the range R3 in which the rotation angle θ (operation amount) of the lever 11 (see Fig. 4) is 0 degrees to the maximum angle θ_M (maximum operation amount). Thus, the forward signal output 242 outputs, to an engine controller 3, the output signal S having the output voltage value V (high output voltage value V) at which the opening degree of the throttle valve 22 increases as the rotation angle θ increases over the range R3 in which the rotation angle θ of the lever 11 is 0 degrees to the maximum angle θ_M. The output voltage value V including the limit output voltage value Vr as an upper limit and the rotation angle θ have a substantially linear function relationship. Thus, the slope of the output voltage value V with respect to the rotation angle θ in the characteristics information 252b (solid line) is smaller than the slope of the output voltage value V with respect to the rotation angle θ in the range R3 of non-limitation information (dotted line).

[0067] In the characteristics information 252b, the output voltage value V corresponding to the maximum angle θ_M becomes the limit output voltage value Vr. The remaining structures of the second preferred embodiment are similar to those of the first preferred embodiment.

[0068] According to the second preferred embodiment, the following advantageous effects are achieved.

[0069] According to the second preferred embodiment, the forward signal output 242 outputs, to the engine controller 3, the output signal S having the output voltage value V at which the throttle opening degree increases as the rotation angle θ increases over the range R3 from a rotation angle θ of 0 degrees to the maximum angle θ_M. Accordingly, the output voltage value V corresponding to the rotation angle θ is output (the throttle opening degree is adjusted) over the range R3 from the rotation angle θ of 0 degrees to the maximum angle θ_M while the upper limit of the output voltage value V is limited to the limit output voltage value Vr, and thus while the small boat 200 complies with horsepower regulations, the output voltage value V is more precisely adjusted as compared with the case in which the output signal S having the limit output voltage value Vr (constant value) at the rotation angle θ equal to or more than the threshold angle θt is output.

[0070] According to the second preferred embodiment, the forward signal output 242 outputs, to the engine controller 3, the output signal S having the output voltage value V at which the throttle opening degree increases as the rotation angle θ increases such that the rotation angle θ and the output voltage value V have a substantially linear function relationship over the range R3 from a rotation angle θ of 0 degrees to the maximum operation amount θ_M. Accordingly, even when the upper limit of the output voltage value V is limited to the limit output voltage value Vr, a rider P more intuitively adjusts the output voltage value V as compared with the case in which the rotation angle θ and the output voltage value V have a relatively complicated relationship (output characteristics) other than the linear function. The remaining effects of the second preferred embodiment are similar to those of the first preferred embodiment.

Third Preferred Embodiment

[0071] The structure of a small boat 300 according to a third preferred embodiment is now described with reference to Figs. 8 and 9. In the small boat 300 according to the third preferred embodiment, a forward signal output 342 includes a first storage 352 that stores limitation characteristics information 352a and a second storage 353 that stores non-limitation characteristics information 353a. In the third preferred embodiment, the same structures as those of the first and second preferred embodiments are denoted by the same reference numerals, and description thereof is omitted.

[0072] As shown in Fig. 8, the small boat 300 according to the third preferred embodiment includes a handle unit 306. The handle unit 306 includes a forward operating unit 310a and a rearward operating unit 310b. The forward operating unit 310a includes the forward signal output 342. The forward signal output 342 includes a processor 351, the first storage 352 that stores the limitation characteristics information 352a, and the second storage 353 that stores the non-limitation characteristics information 353a. The limitation characteristics information 352a is similar to the characteristics information 52b (see Fig. 6) according to the first preferred embodiment. As shown in Fig. 9, in the non-limitation characteristics information 353a, an output voltage value V including a maximum output voltage value V_M as an upper limit and a rotation angle θ are associated with each other. The limitation characteristics information 352a is an example of "output limitation characteristics information". The non-limitation characteristics information 353a is an example of "output non-limitation characteristics information".

[0073] As shown in Fig. 8, according to the third preferred embodiment, the forward operating unit 310a includes a setter 360 that sets one of the limitation characteristics information 352a and the non-limitation characteristics information 353a. The setter 360 includes a setting operator 361 and a setting switch 362.

[0074] As shown in Fig. 10, the setting operator 361 is disposed on an operating unit housing 313 of the forward operating unit 310a, and is a push button, for example. Preferably, one operation method (pressing for a short time, for example) of the existing operator of the forward operating unit 310a is changed to another operation method (pressing for a long time, for example) such that the operation is received as an operation on the setting operator 361.

[0075] The setting switch 362 is a switch that switches between a state in which the processor 351 is connected to the first storage 352 and a state in which the processor 351 is connected to the second storage 353 according to an operation on the setting operator 361.

[0076] The forward signal output 342 outputs an output signal S based on the limitation characteristics information 352a to an engine controller 3 when the processor 351 is connected to the first storage 352, and outputs an output signal S based on the non-limitation characteristics information 353a to the engine controller 3 when the processor 351 is connected to the second storage 353.

[0077] Thus, when a rider P operates the small boat 300 in an area in which the upper limit of the horsepower corresponding to a limit output voltage value Vr is regulated, or when a rider P not permitted to operate the small boat 300 having horsepower that exceeds the horsepower corresponding to the limit output voltage value Vr operates the small boat 300, the forward signal output 342 outputs the output signal S based on the limitation characteristics information 352a to the engine controller 3 due to setting of the setter 360. When the rider P operates the small boat 300 in an area in which the horsepower is not regulated, for example, the forward signal output 342 outputs the output signal S based on the non-limitation characteristics information 353a to the engine controller 3 due to setting of the setter 360. Note that the rearward operating unit 310b is structurally similar to the forward operating unit 310a. The remaining structures of the third preferred embodiment are similar to those of the first preferred embodiment.

[0078] According to the third preferred embodiment, the following advantageous effects are achieved.

[0079] According to the third preferred embodiment, the forward operating unit 310a includes the setter 360 that sets one of the limitation characteristics information 352a and the non-limitation characteristics information 353a in which the output voltage value V including the maximum output voltage value V_M as an upper limit and the rotation angle θ are associated with each other. Furthermore, the forward signal output 342 outputs the output signal S having the output voltage value V corresponding to the rotation angle θ to the engine controller 3 based on one of the limitation characteristics information 352a and the non-limitation characteristics information 353a set by the setter 360. Accordingly, setting of the limitation characteristics information 352a and the non-limitation characteristics information 353a is switched such that output signals S having different output voltage values V as upper limits are output from the forward signal output 342 using the same type of engine 2 (small boat 300). Consequently, the upper limit of the output voltage value V of the output signal S is changed according to the limited horsepower using the same type of engine 2 (small boat 300), and thus even when the rider P is changed (to a rider with a different license) or even when the small boat 300 is moved across countries in which different horsepower regulations are set up, the small boat 300 complies with horsepower regulations.

[0080] According to the third preferred embodiment, the setter 360 includes the setting operator 361 that receives an operation of setting one of the limitation characteristics information 352a and the non-limitation characteristics information 353a. Accordingly, the rider P or a setting worker operates the setting operator 361 to easily set (select) one of the limitation characteristics information 352a and the non-limitation characteristics information 353a.

[0081] According to the third preferred embodiment, the forward signal output 342 includes the first storage 352 that stores the limitation characteristics information 352a and the second storage 353 that stores the non-limitation characteristics information 353a. Accordingly, the limitation characteristics information 352a and the non-limitation characteristics information 353a are stored in the first storage 352 and the second storage 353 of the forward signal output 342, and thus the output signal S is generated using the limitation characteristics information 352a and the non-limitation characteristics information 353a stored in the first storage 352 and the second storage 353 without providing the limitation characteristics information 352a and the non-limitation characteristics information 353a separately from the forward signal output 342 (small boat 300). Thus, the limitation characteristics information 352a and the non-limitation characteristics information 353a are written in the first storage 352 and the second storage 353 of the forward signal output 342 such that the forward signal output 342 easily outputs the output signal S corresponding to the limitation characteristics information 352a or the non-limitation characteristics information 353a. The remaining effects of the third preferred embodiment are similar to those of the first preferred embodiment.

Fourth Preferred Embodiment

[0082] The structure of a small boat 400 according to a fourth preferred embodiment is now described with reference to Figs. 11 and 12. In the fourth preferred embodiment, when a lever 11 is at a maximum angle θ_M, an output signal S is output in a state in which a maximum output voltage value V_M of a maximum signal S_M output from a maximum signal output 442a is reduced to a limit output voltage value Vr. In the fourth preferred embodiment, the same structures as those of the first to third preferred embodiments are denoted by the same reference numerals, and description thereof is omitted.

[0083] As shown in Fig. 11, the small boat 400 according to the fourth preferred embodiment includes a handle unit 406. The handle unit 406 includes a forward operating unit 410a and a rearward operating unit 410b. The forward operating unit 410a includes a forward signal output 442. The forward signal output 442 includes the maximum signal output 442a that outputs the maximum signal S_M, which is a signal having the maximum output voltage value V_M, when the rotation angle θ of the lever 11 is the maximum angle θ_M, and an output limiter 442b that outputs the output signal S in a state in which the maximum output voltage value V_M of the maximum signal S_M output from the maximum signal output 442a is reduced to the limit output voltage value Vr.

[0084] Specifically, the maximum signal output 442a includes a processor 451a and a storage 452a that stores non-limitation characteristics information 353a (similar to the non-limitation characteristics information 353a according to the third preferred embodiment). The maximum signal output 442a outputs an output signal Sa having the maximum output voltage value V_M as an upper limit to the output limiter 442b. When the output signal Sa has the maximum output voltage value V_M, the same is defined as the maximum signal S_M.

[0085] The output limiter 442b lowers the output voltage value V of the output signal Sa. For example, the output limiter 442b includes a resistor. Thus, as shown in Fig. 12, the output limiter 442b converts the output signal Sa having the maximum output voltage value V_M as an upper limit to the output signal S having the limit output voltage value Vr as an upper limit, and outputs the same to an engine controller 3. Note that the rearward operating unit 410b is structurally similar to the forward operating unit 410a. The remaining structures of the fourth preferred embodiment are similar to those of the first preferred embodiment.

[0086] According to the fourth preferred embodiment, the following advantageous effects are achieved.

[0087] According to the fourth preferred embodiment, the forward signal output 442 includes the maximum signal output 442a that outputs the maximum signal S_M, which is a signal having the maximum output voltage value V_M, when the rotation angle θ is the maximum angle θ_M, and the output limiter 442b that outputs the output signal S in a state in which the maximum output voltage value V_M of the maximum signal S_M output from the maximum signal output 442a is reduced to the limit output voltage value Vr when the rotation angle θ is the maximum angle θ_M. Accordingly, the output limiter 442b is added to the structure of the existing maximum signal output 442a such that the forward signal output 442 easily outputs the output signal S having the limit output voltage value Vr as an upper limit. The remaining effects of the fourth preferred embodiment are similar to those of the first preferred embodiment.

[0088] The preferred embodiments described above are illustrative in all points and not restrictive. The extent of the present invention is not defined by the above description of the preferred embodiments but by the scope of the claims, and all modifications within the meaning and range equivalent to the scope of the claims are further included.

[0089] For example, while the small boat is preferably a PWC and a water jet propelled boat in each of the first to fourth preferred embodiments described above, the present invention is not restricted to this. For example, a propulsion device (an inboard motor or an outboard motor) other than a jet may alternatively be provided in the small boat.

[0090] While the rotation angle of the lever is preferably used as the operation amount in each of the first to fourth preferred embodiments described above, the present invention is not restricted to this. For example, the parallel movement amount of the operator that moves in parallel may alternatively be used as the operation amount, or the grip may alternatively be rotatable and the rotation angle of the grip may alternatively be used as the operation amount.

[0091] While the forward signal output preferably outputs, to the engine controller, the output signal having the output voltage value that increases as the rotation angle increases such that the rotation angle of the lever and the output voltage value have a substantially linear function relationship in each of the first to fourth preferred embodiments described above, the present invention is not restricted to this. For example, the forward signal output may alternatively output, to the engine controller, the output signal having the output voltage value that increases as the rotation angle increases such that the rotation angle of the lever and the output voltage value have a quadratic function or logarithmic function relationship.

[0092] While the rotation angle of the rotation shaft that integrally rotates with the lever is preferably detected by the angle detector that faces the rotation shaft in the radial direction (no mechanical wire is preferably provided) in each of the first to fourth preferred embodiments described above, the present invention is not restricted to this. For example, a mechanical wire may alternatively be connected to the rotation shaft, and the rotation angle may alternatively be detected by the angle detector disposed away from the rotation shaft (in the vicinity of the engine controller, for example).

[0093] While the output value is preferably an output voltage value in each of the first to fourth preferred embodiments described above, the present invention is not restricted to this. For example, the output value may alternatively be an output current value.

[0094] While the engine controller preferably performs control such that the throttle opening degree increases as the output voltage value increases in each of the first to fourth preferred embodiments described above, the present invention is not restricted to this. For example, the engine controller may alternatively perform control such that the throttle opening degree increases as the output voltage value decreases. In this case, the "upper limit of the output voltage value" indicates the smallest output voltage value at which the throttle opening degree becomes maximum.

[0095] While the forward signal output preferably outputs the output voltage value corresponding to the rotation angle with the processor that refers to the characteristics information stored in the storage in each of the first to fourth preferred embodiments described above, the present invention is not restricted to this. For example, the forward signal output may alternatively include a combination (hardware) of a plurality of electric components disposed on the board.

[0096] While the characteristics information is preferably set from one piece of limitation characteristics information and one piece of non-limitation characteristics information in the third preferred embodiment described above, the present invention is not restricted to this. For example, the characteristics information may alternatively be set from a plurality of pieces of limitation characteristics information and one piece of non-limitation characteristics information.

[0097] While the output limiter 442b preferably includes a resistor that lowers the voltage value, and the output signal S is preferably output in a state in which the maximum output voltage value V_M is reduced to the limit output voltage value Vr in the fourth preferred embodiment described above, the present invention is not restricted to this. For example, the output limiter 442b may alternatively include an electronic component that serves as a limiter that limits a voltage value exceeding the limit output voltage value Vr to the limit output voltage value Vr, and when the rotation angle θ is equal to or more than the threshold angle θt, the output signal S may alternatively be output in a state in which the maximum output voltage value V_M of the maximum signal S_M output from the maximum signal output 442a is limited to the limit output voltage value Vr.

[0098] While on the lever, it is preferably distinguishable by color that the upper limit of the output voltage value of the output signal is limited to the limit output voltage value in the first to fourth preferred embodiments described above, the present invention is not restricted to this. For example, an indicator (sticker) indicating that the upper limit of the output voltage value of the output signal is limited to the limit output voltage value may alternatively be affixed to the operating unit housing or the grip such that it is distinguishable.

[0099] While the lower limit of the output voltage value is preferably set as the abnormality detection output voltage value in each of the first to fourth preferred embodiments described above, the present invention is not restricted to this. For example, when abnormality detection is not required, the lower limit of the output voltage value may alternatively be 0 [V].

Claims

1. A small boat (100, 200, 300, 400) comprising:

a throttle operator through which a throttle opening degree of an engine (2) is controlled;

an engine controller (3) that is configured to control the throttle opening degree; and

a forward signal output (42, 242, 342, 442) that is configured to output, to the engine controller (3), an output signal (S) having an output value at which the throttle opening degree increases as an operation amount of the throttle operator increases, and is configured to output, to the engine controller (3), the output signal (S) having, as an upper limit, a limit output value at which the throttle opening degree becomes smaller than that at a maximum output voltage value (V_M) at which the throttle opening degree becomes maximum.

2. A small boat (100, 200, 300, 400) according to claim 1, wherein the forward signal output (42, 242, 342, 442) is configured to output the output signal (S) having the limit output value to the engine controller (3) when the operation amount is a maximum operation amount.

3. A small boat (100, 200, 300, 400) according to claim 2, wherein the forward signal output (42, 242, 342, 442) is configured to output the output signal (S) having the limit output value to the engine controller (3) when the operation amount is equal to or larger than an operation amount threshold that is smaller than the maximum operation amount.

4. A small boat (100, 200, 300, 400) according to claim 2 or 3, wherein the forward signal output (42, 242, 342, 442) is configured to output, to the engine controller (3), the output signal (S) having the output value at which the throttle opening degree increases as the operation amount increases over a range from the operation amount of 0 to the maximum operation amount.

5. A small boat (100, 200, 300, 400) according to claim 4, wherein the forward signal output (42, 242, 342, 442) is configured to output, to the engine controller (3), the output signal (S) having the output value at which the throttle opening degree increases as the operation amount increases such that the operation amount and the output value have a linear function relationship over the range from the operation amount of 0 to the maximum operation amount.

6. A small boat (100, 200, 300, 400) according to any of claims 2 to 5, wherein
the throttle operator is rotationally operated;
the small boat (100, 200, 300, 400) further comprises an angle detector (41) that is configured to detect a rotation angle (θ) of the throttle operator; and
the forward signal output (42, 242, 342, 442) is configured to output the output signal (S) having the limit output value, assuming that the operation amount is the maximum operation amount, to the engine controller (3) when the rotation angle (θ) that is detected by the angle detector (41) is a maximum angle (θ_M).

7. A small boat (100, 200, 300, 400) according to claim 6, wherein
the throttle operator extends from a rotation shaft (14) disposed in a vicinity of a grip (12) grasped by a boat operator (P) in a radial direction of the rotation shaft (14), and is a lever (11) that is configured to be rotated about the rotation shaft (14) toward the grip (12);
the angle detector (41) faces the rotation shaft (14) in the radial direction, and is configured to detect a rotation angle (θ) of the rotation shaft (14) as the operation amount; and
the forward signal output (42) is configured to output the output signal (S) having the limit output value, assuming that the operation amount is the maximum operation amount, to the engine controller (3) when the rotation angle (θ) that is detected by the angle detector (41) is the maximum angle (θ_M).

8. A small boat (100, 200, 300, 400) according to any of claims 1 to 7, wherein the forward signal output (42, 242, 342, 442) is configured to output the output signal (S) having the output value (V) corresponding to the operation amount to the engine controller (3) based on output limitation characteristics information (52b, 252b, 352a) in which the output value including the limit output value as an upper limit and the operation amount are associated with each other.

9. A small boat (100, 200, 300, 400) according to claim 8, wherein
in the output limitation characteristics information (52b, 252b, 352a), the operation amount and an output voltage value as the output value are associated with each other; and
the forward signal output (42, 242, 342, 442) is configured to output the output signal (S) having a limit output voltage value (Vr), which is the output voltage value corresponding to the limit output value, as an upper limit to the engine controller (3).

10. A small boat (300) according to claim 8 or 9, further comprising a setter (360) that is configured to set one of the output limitation characteristics information (352a) and output non-limitation characteristics information (353a) in which the output value including the maximum output voltage value (V_M) as an upper limit and the operation amount are associated with each other; wherein
the forward signal output (342) is configured to output the output signal (S) having the output value corresponding to the operation amount to the engine controller (3) based on one of the output limitation characteristics information (352a) and the output non-limitation characteristics information (353a) set by the setter (360).

11. A small boat (300) according to claim 10, wherein the setter (360) includes a setting operator (361) that is configured to receive an operation of setting one of the output limitation characteristics information (352a) and the output non-limitation characteristics information (353a).

12. A small boat (300) according to claim 10 or 11, wherein the forward signal output (342) includes a storage (352, 353) that is configured to store the output limitation characteristics information (352a) and the output non-limitation characteristics information (353a).

13. A small boat (100, 200, 300, 400) according to any of claims 2 to 7, wherein the forward signal output (442) includes a maximum signal output (442a) that is configured to output a maximum signal (S_M), which is a signal having the maximum output voltage value (V_M), when the operation amount is the maximum operation amount, and an output limiter (442b) that is configured to output the output signal (S) in a state in which the maximum output voltage value (V_M) of the maximum signal (S_M) output from the maximum signal output (442a) is reduced to the limit output value when the operation amount is the maximum operation amount, or is configured to output the output signal (S) in a state in which the maximum output voltage value (V_M) of the maximum signal (S_M) output from the maximum signal output (442a) is limited to the limit output value when the operation amount is equal to or larger than an operation amount threshold that is smaller than the maximum operation amount.

14. A small boat (100, 200, 300, 400) according to any of claims 1 to 13, further comprising a throttle operating device main body (10a, 210a, 310a, 410a) in which the throttle operator and the forward signal output (42, 242, 342, 442) are disposed and being replaceable from a boat body (1) and wherein on the throttle operating device main body (10a, 210a, 310a, 410a), it is visually distinguishable that an upper limit of the output value of the output signal (S) is limited to the limit output value.

15. A throttle operating method for a small boat comprising:

controlling a throttle opening degree; and

outputting, to a engine controller (3), an output signal (S) having an output value at which the throttle opening degree increases as an operation amount of the throttle operator increases, and outputting, to the engine controller (3), the output signal (S) having, as an upper limit, a limit output value at which the throttle opening degree becomes smaller than that at a maximum output voltage value (V_M) at which the throttle opening degree becomes maximum.

Drawing